Vacuum tray replacement for cutting lightweight materials

Aha now that I know where to look for static pressure ratings this one would slot in with no modification and provide about 5x the vacuum:

https://www.digikey.com/en/products/detail/sanyo-denki-america-inc/9CRH0412P5J001/7622262

Question is whether or not my mesh would withstand the increase. I can math it out now. 0.03 psi * 11” x 19.5” yields a total ideal downforce of 6.4 lbs. adjusting for efficiency issues (leaks, etc) I’d suspect it’s closer to 6 lbs. Using this new fan would jump it up to 30 lbs. It’d probably work, I’d think.

And yeah a nice small high pressure centrifugal fan would be nice. I looked but didn’t get too far.

This is even higher:
https://www.digikey.com/en/products/detail/sanyo-denki-america-inc/9CRJ0412P5J001/13245514

0.34 psi static pressure. ~74.6 pounds of total downforce. That sounds like overkill for my mesh.

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Surprise, my fan arrived as twins!

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Imagine if the force on the paper was 75 pounds instead of six?
You have me thinking that “supports” of zig-zaggy aluminum flashing aligned with the airflow and correct height glued down could provide that push back to keep your top surface from sagging like that,

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Twins! Congratulations!

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What everyone else said. if you don’t want to do the labor, maybe hire someones to do the work and ship it and you keep a commission. but the minute you do, someone will copy it and do it for less. and a patent wouldn’t be worth it, if you could get one. still a great idea.

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I wish I were that cool at any age.

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be who you are and don’t give a damn what anyone else thinks.

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Yes… In moderation.

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“Moderation is for monks. Everything to excess!”

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Amen

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Moderation in all things (including moderation).

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Skater tangent: Pretty sure those two were in an H-Street video back in the day.

@evansd2
This thread is sofa king amazing. I need this thing. I’ve removed my fan, so I’m thinking I’ll just plug it in and use the GF for power (i have a basic)… And yea, the sagging issue I think can be solved with properly cut (with lots of holes?) and positioned supports. I’m confident my inline fan will still remove smoke fine, but as you said, it’s paper and isn’t going to smoke too much.

This really is a brilliant idea and GF needs to get in the game. Well done Man.

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Excess! Started with the one red blower (1.5hp Penn/850cfm)), then decided to add a leftover I had from another laser (not a big one, like 400 CFm),… then decided I needed another big red one, so a total of two 1.5hp blowers.

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This is a cool idea because the Glowforge would trigger the fan on and off as well. One thing to watch for here though if you do it is a potential discrepancy in the measured height vs the actual height for when vacuum is applied.

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Yeah that’s why I use set focus. I could measure it by hand once and use that but I’ve been lazy. :slight_smile:

As for the power supply I find it very easy to use a wall plug. I think it’d be easier than trying to wrangle the power connection over by the fan, but I’m sure it could work. Curious to see if anyone tries it.

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Good idea. I’ve just lived with flyaways. I’ve been using neodymium magnets to secure the corners and edges of paper that is to be cut.

It seems that one might be able to place the fan(s) inside the vacuum table (if placed under the rim, it/they should not be exposed to the laser). This might simplify construction? I may build one, but I will cut the parts using my table saw. Some days, the traditional way is the one I choose. Also, I have a Glowforge Basic, so cut size is a limitation.

I’ll have to look in my “used supplies” box to see if I have suitable fans. I know I have discarded a number of these in the past.

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That’s exactly how it’s set up.

The fans are 40mm square, or 1.57". That’s within range, but if you’re using 0.125 material your total thickness is bumping right up against physical limits with the air assist fan scoop. which leaves you almost no room for a screen assembly.

Instead, I settled on this design, with a 1.3" main tray box, and a 1.85" total height manifold box attached to the rear with spots for 2 fans. The 1.3" main tray height is just about crumb tray height, then the mesh is in a .375" thick frame at about the 0.25" height. Accounting for mesh flex it probably ends up with an effective material height of 0.2", but I just use set focus and am done with it.

My initial prototype actually had the fan mounted directly to the side of a 40mm tall tray box (eliminating the extra height required by the top and bottom of an enclosure), so the height of the tray was at 1.57". You have about 0.25" to work with at that point – doable, but I don’t like designs that are bumping up against physical limits without much margin for error. It’s too easy for something to go wrong and blow the project.

I wouldn’t recommend this. This presents a fairly significant fire risk or at the very least a flyaway can block your laser and prevent a later cut. Flyaways are bad all around.

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Oh, good. When you get it nailed down, I can bug you for details. :wink:

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Just like you didn’t!

(I’m still a little disappointed. Two of you would be twice as nice!)

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